Self-starting synchronous motor



July 9, 1929.

P. P. HORN] SELF STARTING SYNCHRONOUS MOTOR Original Filed Dec. 24, 192'? Patented July 9, 19 29.

UNITED STATES PATENT oFFIcE.

SELF-STARTING SYNCHRONOUS MOTOR.

Original application filed December 24, 1927, Serial No. 242,447. Divided and this application filed December 6,1928. Serial No. 324,123.

This is a divisional application from ap- The helical turns may be circular as plicants case, Serial No. 242,447, filed Deshown in Figure 3 or of any other operatable cember 24, 1927. shape. They may be arranged with a The invention relates to alternating curslightly diagonalbias to the axis of rotation 5 rent motors of the induction type when a I as shown in Figure 2, but in every form'they small motor is desired to have a strong selfmust be made of steel with a slight amount starting characteristic combined with a synof remanence to insure their running in perchronizing characteristic that will, when the feet synchronism and they must have an even motor approaches full speed, cause the motor number of turns as for example twelve as 10 to run insynchronism with the alternations shown in Figure 1. The number of turns of theelectric current supplied to it. may vary from a minimum to a maximum; The object .of the present invention is the the minimum being found when the rotor production of a rotor for such motors that refuses to start and the maximum when will combine extreme simplicity and lightthe rotor fails to run in synchronism 'with 15 ness with the characteristics of self-startthe electric alternations.

ing and synchronous running accentuated to I have found that a rotor of this form a maximum degree. gives the maximum effort both as to self- The invention comprises the combination starting and as to synchronous running. with the ordinary rotative field of a rotor I claim go of toric form, the torus being made of an 1. An induction rotor comprising a shaft, even number of convolutions of a steel wire a helix of iron wire bent around the shaft which has a slight amount of magnetic in the 'form of a torus.

remanence. 2. An induction rotor comprising a shaft, The invention is ilustrated in the accoma helix of iron wire having appreciable mag- 25 panying drawings, in which netic' remanence surrounding the shaft in Figure 1 is an end view of a motor parthe form of a torus.

- tially sectioned; 3. Aninduction rotor comprising a shaft, Fi re 2 is an end view showing a modia plurality of helices of iron wire surround fied orm of torus; mg the shaft in toric form.

, Figure 3 is anaxial section of an element 4. A selfistarting synchronous motor comof the rotor; and rising in combination a rotating magnetic Fi re 4 is an axial section of an asgeld, a rotor made of steel wire in the form semb y of three tori on a common axis. of a helical torus, the steel having a slight 5 As .shown the rotor 1 is made in the form amount of remanence and an even number a of a circular ring or torus from a helix of of helical turns. steel wire. The torus is mounted on and se- 5. A 'combinationaccording to claim 4 in cured to a shaft 2 of non-magnetic material which the torus is mounted on a shaft of and rotates with a field formed by electronon-magnetic material. magnets having lain poles 4 and shaded Q v 40 poles 5 in the we known manner of formj PAUL P. HORNL g rotative fields from single phase a1ter-- 1 nating current.- 1 

